DavidH, bbearden
My soil is very rocky it consists mostly of flint rock (the size of a man’s head and smaller) and red clay. The driver does a good job putting the 4-6” posts in. I haven’t put in any steel posts or pipe yet, but I have watched two different people in my area put them in. They seem to go in in about half the time that the wood ones do. In other words, really fast.
I did hit one rock that was larger than the post in diameter. I had to pull the post back out. When I looked at the bottom of the post, you could see that the whole bottom of the post had been contacting the rock